Inclusion body myositis and systemic lupus erythematosus.

Inclusion body myositis (IBM) has been recognized as a distinct type of idiopathic inflammatory myopathy. Previous reports have emphasized the absence of immunologic abnormalities and lack of response to corticosteroid therapy in patients with IBM. We report a case of IBM associated with systemic lupus erythematosus and modest response of the myopathy to corticosteroid therapy. The clinical and immunologic features of IBM are more diverse than previously appreciated.